Once you have logged in, click on the profile picture in the top right corner and your account information should appear below.

Once you see the drop-down menu, just scroll to the bottom of the menu to the "Services" section.

Once there, just click "connect" next to Google Drive

Once you click "connect", you will be prompted to sign into your Google account and you should now be able to link your Google Drive account to your Hightail account. If you want to disconnect your Google Drive, just click "Disconnect" next to the Google Drive icon.